Air purifier using ultraviolet rays

ABSTRACT

An air purifier includes a case having an air inlet and an air outlet, a fan disposed adjacent the air inlet, a UV LED unit and a filter unit arranged over the fan along a flow path of air, and a fluid control structure disposed between the fan and the filter unit.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application claims priority to Korean application numbers10-2013-0106883, and 10-2013-0106884, both filed on Sep. 5, 2013, thecontents which are incorporated by reference in their entirety.

BACKGROUND

The disclosure of this patent document relates to a technology for anair purifier including an air purifier using ultraviolet (UV) rays.

Recently, the quality of air in Korea has been rapidly degraded. Forexample, air contaminants caused by the rapid industrialization of Chinacover the Korean peninsula with yellow dust. Thus, the concentration ofair contaminants including harmful heavy metals in the air of Korea hasexceeded to a worrying degree. Furthermore, the quality of indoor air inmany buildings has been degraded by air contaminants such as fine dust,formaldehyde, and airborne bacteria. Thus, a lot of people have beensaid to suffer from the sick building syndromes with symptoms such assneeze, cough, fatigue, and dry and sore nose, eyes, and throat.

Such environmental conditions are or can be some of the factorsincreasing the demand for an air purifier capable of purifyingcontaminated air. Most of air purifiers which are currently used incommon include or can include various filters provided with the airpurifiers, and receive the contaminated air and purify the contaminatedair by physically filtering or adsorption-filtering contaminantparticles through the filters.

Recently, there has been proposed a method which directly sterilizes theair using UV rays or purifies the air through radicals generated byreactions between a photocatalyst filter and UV rays. An example of suchan air purification method using UV rays has been disclosed in KoreanPatent Laid-open Publication No. 2011-0096258.

Fans used in air purifiers may be classified into axial-type fans andcentrifugal fans. The axial-type fans generate air flow in the directionparallel to the rotation axis of an impeller, and a domestic fan may betaken as an example of the axial-type fans. The centrifugal fans maytake air flow in the direction of the rotation axis thereof, butdischarge air flow in the direction perpendicular to the rotation axisthereof, and a blower fan may be taken as an example of the centrifugalfans. An example of the technique related to the air purifier employingthe centrifugal fan has been disclosed in Korean Patent Laid-openPublication No. 2011-0057562.

SUMMARY

In one embodiment, an air purifier includes a case having an air inletand an air outlet, a fan disposed inside the case and adjacent the airinlet, an ultraviolet (UV) light emitting diode (LED) unit and a filterunit arranged inside the case over the fan along a flow path of air, anda fluid control structure disposed inside the case between the fan andthe filter unit. The fluid control structure controls an air flow alongthe flow path of air between an outlet of the fan and the filter unit.

In another embodiment, an air purifier includes a case having an airinlet and an air outlet, and an air purification unit disposed along aflow path of air within the case. The air purification unit includes aprinted circuit board (PCB) having through-holes formed on the PCB, UVLEDs arranged on the PCB, and a light reflecting structure disposed tosurround the UV LEDs. The air flows along the flow path within the caseand through the through-holes and UV LEDs irradiate UV rays onto the airthat passes through the through-holes to sterilize the air.

In another embodiment, an air purifier includes a case having an airinlet and an air outlet, a fan disposed inside the case and adjacent tothe air inlet, a filter unit arranged inside the case and over the fanalong a flow path of air leading to the air outlet, the filter unitoperable filter the air flow, an ultraviolet (UV) unit inside the caseto direct UV light to a location in the flow path of air, causingsterilization of the air flow, a fluid control structure disposed insidethe case between the fan and the filter unit, and a light reflectingstructure disposed inside the case to surround the UV LED unit to spreadthe UV light irradiated to the filter unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates an exemplary air purifier in accordancewith a first embodiment of the disclosed technology.

FIG. 2 is a schematic cross-sectional view of the air purifier of FIG.1.

FIG. 3 is a schematic plan view of an exemplary UV light source inaccordance with an embodiment of the disclosed technology.

FIG. 4 schematically illustrates an exemplary air purifier in accordancewith a second embodiment of the disclosed.

FIG. 5 is a schematic plan view of an exemplary UV light source inaccordance with an embodiment of the disclosed technology.

FIG. 6 schematically illustrates an exemplary air purifier in accordancewith a third embodiment of the disclosed technology.

FIG. 7 is a schematic cross-sectional view of the air purifier of FIG.6.

FIG. 8 is a schematic cross-sectional view of an exemplary air purifierin accordance with a fourth embodiment of the disclosed technology.

FIG. 9A is a schematic cross-sectional view of an exemplary air purifierin accordance with a fifth embodiment of the disclosed technology.

FIG. 9B is a schematic plan view of an exemplary fluid control structureapplied to the air purifier of FIG. 9A.

FIG. 10A is a schematic cross-sectional view of an exemplary airpurifier in accordance with a sixth embodiment of the disclosedtechnology.

FIG. 10B is a schematic plan view of an exemplary fluid controlstructure applied to the air purifier of FIG. 10A.

FIG. 11A is a schematic cross-sectional view of an exemplary airpurifier in accordance with a seventh embodiment of the disclosedtechnology.

FIG. 11B is a schematic plan view of an exemplary UV LED unit applied asa fluid control structure of the air purifier of FIG. 11A.

FIG. 12 is a schematic cross-sectional view of an exemplary air purifierin accordance with an eighth embodiment of the disclosed technology.

FIG. 13A is a cross-sectional view of the air purifier of FIG. 12, seenfrom a direction A.

FIG. 13B is a cross-sectional view of the air purifier of FIG. 12, seenfrom a direction B.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Embodiments of the disclosed technology on air purifiers willhereinafter be described in detail with reference to the accompanyingdrawings. It should be noted that the drawings are not to precise scaleand may be exaggerated in some aspects, e.g. in thickness of lines orsizes of certain components for descriptive convenience and clarityonly.

In embodiments of the disclosed technology, the term such as ‘first’ or‘second’ can be used to distinguish between members, but does not limita specific member or indicate a specific order. Furthermore, when anelement is referred to as being positioned on another element or ‘over’,‘under’, and ‘by’ another element, the element can indicate the relativepositional relationship between the elements. Thus, the former elementmay be directly contacted with the latter element, or an additionalelement may be interposed at the interface between the elements.Furthermore, when an element is referred to as being ‘coupled’ or‘connected’ to another element, it may indicate that the former elementis directly coupled or connected to the latter element or an additionalelement is interposed therebetween. Throughout the specification, likereference numerals denote substantially the same components.

FIG. 1 schematically illustrates an air purifier in accordance with afirst embodiment of the present disclosure. FIG. 2 is a schematiccross-sectional view of the air purifier of FIG. 1. Referring to FIGS. 1and 2, the air purifier 100 can include a case 110 and an airpurification unit 20. The air purification unit 20 can include a UVlight source 210 and a filter unit 220. The UV light source 210 isprovided as part of the air sterilization mechanism that is built intothe device. Examples below provide two different UV emissions at twodifferent UV spectral ranges for two different UV-based airsterilization processes.

The case 110 can include an air inlet 112 and an air outlet 114, andform a body part of the air purifier 100. Referring to the drawings inFIGS. 1 and 2, an available volume of space representing an air flowpath from a top of the UV light source 210 upward to the air outlet 114created by arrangements of internal structures of the case 110 can havesubstantially the same cross-sectional area throughout the air flowpath. In other embodiments, however, cross-sectional areas formed alongthe air flow path may be different from each other or at various pointsof the air flow path, and modified or can be modified in variousmanners.

In the case 110 adjacent to the air inlet 112, a fan 130 can be disposedto be substantially aligned with the inlet 112 to expedite flow of airintroduced into the case 110. The fan 130 can include a blower fan oraxial-type fan, for example. FIGS. 1 and 2 illustrate a blower fan, forexample, but the fan 130 is not limited to a blower fan. The fan 130 caninclude an inlet 132 adjacent to and substantially aligned with the airinlet 112 to expedite the entry of the air into the case. The fan 130can include an outlet 134 for discharging introduced air towards a fluidcontrol structure or an air duct 140.

When a blower fan is applied or used as the fan 130 as illustrated inthe drawings of FIGS. 1 and 2, the outlet 134 of the fan 130 can have asmaller cross-sectional area than the cross-sectional area of the case110. In this case, the air discharged from the outlet 134 of the fan 130can stay around or near the outlet 134 or flow toward a bottom of thecase 110. Thus, as illustrated in the drawings of FIGS. 1 and 2, a fluidcontrol structure or an air duct 140 can be disposed to couple with andextend from the outlet 134 of the fan 130 toward an inner wall of thecase 110. Thus, the air discharged from the outlet 134 of the fan 130can uniformly or substantially uniformly flow to an internal space ofthe case 110 feeding the air purification unit 20. As illustrated in thedrawings of FIGS. 1 and 2, the fluid control structure or air duct 140can include an air duct for controlling air flow. The fluid controlstructure or air duct 140 can be not only disposed to extend from theoutlet 134 of the fan 130 toward the inner wall of the case 110, butalso can be disposed at a proper position between the air inlet 112 andthe air purification unit 20 to provide substantially uniform flow ofair discharged from the outlet of the fan 130 towards the airpurification unit 20.

The air purification unit 20 can be disposed over the fan 130 to receiveand purify air discharged from the outlet 134 of the fan 130. Asillustrated in the drawings of FIGS. 1 and 2, the UV light source 210and the filter unit 220 can be sequentially disposed to have the filterunit 220 above the UV light source 210.

The UV light source 210 can include a printed circuit board (PCB) 211with UV LEDs 212 and 213 that emit UV light at different UV spectralranges and are arranged on the PCB 211, and a light reflecting structure214. The PCB 211 can have through-holes formed on the PCB, through whichair is passed. The light reflecting structure 214 can be disposed tosurround the UV LEDs 212 and 213, and reflect UV rays emitted from theUV LEDs 212 and 213 so as to increase a frequency at which air flowingthrough the through-holes and along the flow path comes in contact withthe emitted UV rays. In one aspect, the light reflecting structure 214can be disposed at the sides of the UV LEDs 212 and 213 so as to have alarger height than the UV LEDs 212 and 213 with a reflecting surface ofthe reflecting structure facing the sides of the UV LEDs 212 and 213 ata predetermined angle with respect to the PCB 211. For example, thelight reflecting structure 214 can be extended toward the inner wall ofthe case 110 as the height of the light reflecting structure 214 isincreased in such a way that a base of the light reflecting structure214 is further away from the inner wall of the case 110 than a top ofthe light reflecting structure 214. In other embodiments, the PCB 211can be disposed in or integrated with the light reflecting structure214.

The UV LEDs 212 and 213 can emit UV rays to the air having passedthrough the through-holes to cause UV-based sterilization of the air intwo different ways. The UV LEDs 212 are sterilization UV LEDs 212, forexample, that emit UV light that is sufficient to directly sterilize theair. THE UV LEDs 213 are photocatalyst UV LEDs 213, for example, thatemit UV light at longer UV wavelengths for causing photocatalystreaction in a photocatalyst material to cause sterilization of the air.The arrangement of the sterilization UV LEDs 212 and photocatalyst UVLEDs 213 on the PCB can be varied to have different configurationsdepending on the specific needs or design considerations. The UV LEDs212 and 213 can be arranged in such a manner that the flow direction ofthe air flowing along the air flow path coincides with the irradiationdirection of the UV rays. For example, the air can flow from the bottomof the case 110 toward the top of the case 110, and the UV LEDs 212 and213 can be arranged on the PCB 211 so as to irradiate UV rays toward thetop of the case 110.

In some implementations, the sterilization UV LEDs 212 can emit UV rayswith a wavelength range 200 nm to 300 nm, and the photocatalyst UV LEDs213 can emit UV rays with a wavelength range of 300 nm to 400 nm, longerthan the UV rays by the wavelengths of sterilization UV LEDs 212.

The filter unit 220 can be disposed over the UV light source 210 so asto face or substantially face the UV LEDs 212 and 213. For example, thefilter unit 220 can include a photocatalyst filter 222 and a collectionfilter 224 which are sequentially positioned over the UV LEDs 212 and213 with the collection filter 224 disposed over the photocatalystfilter 222.

The photocatalyst filter 222 can include a material for providing aphotocatalytic reaction under UV illumination, as a photocatalystmedium. For example, the photocatalyst medium can include but is notlimited to titanium oxide (TiO₂), zinc oxide (ZnO), tungsten oxide(WO₃), or zirconium oxide (ZrO₂). The photocatalyst filter 222 can havea layered-structure including TiO₂ as at least one of the layers of thelayered-structure. The photocatalyst filter 222 can be formed of a layeror layers obtained by coating a material such as metal foam or porousmetal, through which air flow can be passed.

The photocatalyst filter 222 can cause a photocatalytic reaction with UVrays with a wavelength of 300 nm to 400 nm, emitted from the UV LEDs213. When the UV rays are absorbed into the photocatalyst medium,electrons (e−) and holes (+) are formed at a surface of thephotocatalyst medium, and the photocatalyst medium induced electrons canreact with oxygen existing at the surface of the photocatalyst medium soas to generate superoxide negative ions (O²⁻). Furthermore, thephotocatalyst medium induced holes can react with moisture existing inthe air so as to generate hydroxyl radicals (OH—.). The hydroxylradicals generated at this time responsive to the reaction betweenphotocatalyst medium induced holes and moister in the air can oxidizeand decompose organic materials in the air flowing through the air flowpath and through the photocatalyst filter 222. Thus, organic materialssuch as contaminants and malodorous substances within the air introducedinto the air purifier can be decomposed into water and carbon dioxide.Furthermore, the hydroxyl radicals can serve as a strong oxidizing agentto perform sterilization. Thus, the photocatalyst filter 222 candeodorize and sterilize the introduced air flowing through the air flowpath in cooperation with the photocatalyst UV LEDs 213.

The collection filter 224 can perform a function of collecting bacteriawithin the introduced air that flow through the air flow path andthrough the collection filter 224. For this operation, the collectionfilter 224 can have minute holes through which bacteria cannot easilypass. The collection filter 224 can include a filter material which hasa shape bent with respect to the air flow direction, in order toincrease a surface area of the collection filter 224 and improve theamount of bacteria collected per unit area. The bacteria collected inthe collection filter 224 can be sterilized by UV rays with a wavelengthof 200 nm to 300 nm, emitted from the sterilization UV LEDs 212. Thecollection filter 224 can increase the time during which the bacteriawithin the air flowing through the air flow path are exposed to thesterilization UV rays, thereby improving the sterilization efficiency ofthe sterilization UV LEDs 212. In other embodiments, the collectionfilter 224 can include a sterilization agent. The sterilization agentcan additionally increase the sterilization efficiency.

In other embodiments, the air purifier 100 can further include a carbonfilter. The carbon filter can be disposed between the fan 130 and the UVlight source 210 or next to the filter unit 220 before or below thephotocatalyst filter 222 and collection filter 224. The carbon filtercan include active carbon and catalyst to filter out or remove organicchemical materials within the air. Thus, the carbon filter can deodorizethe introduced air flowing through the air flow path.

In other embodiments, at least a part of the inner wall of the case 110can be coated with a light reflecting material. For example, a coatinglayer formed of aluminum or silver, which has high light reflectionefficiency with respect to the inner wall at the top of the UV lightsource 210, can be formed to additionally increase the frequency atwhich the air flowing through the case 110 along the flow path comes incontact with the UV rays.

FIG. 3 is a schematic plan top-down view of an exemplary UV light source(e.g., UV light source 210) in accordance with an embodiment of thepresent disclosure. Referring to FIG. 3, the UV light source 210 caninclude the PCB 211 having through-holes 216 formed therein. Thesterilization UV LEDs 212 and the photocatalyst UV LEDs 213 can bearranged on the PCB 211. As illustrated in FIG. 3, the sterilization UVLEDs 212 and the photocatalyst UV LEDs 213 can be arranged on the PCB211 so as to cross each other or alternate each other. However, thearrangement is not limited to the one shown in FIG. 3, and thesterilization UV LEDs 212 and the photocatalyst UV LEDs 213 can bearranged in various manners.

The light reflecting structure 214 can be disposed to surround thesterilization UV LEDs 212 and the photocatalyst UV LEDs 213. The innerwall of the light reflecting structure 214 can include a coating layerformed of aluminum or silver, which has high light reflectionefficiency. In another embodiment, the light reflecting structure 214can be formed of aluminum or silver. The light reflecting structure 214can be structurally supported by the inner wall of the case 110 and aconnection member or at least one connection member 215 between thelight reflecting structure 214 and the PCB 211. The shape and structureof the connection member 215 can be based on or based at least in parton a variety of publicly-known support structures.

FIG. 4 schematically illustrates an exemplary air purifier in accordancewith a second embodiment of the present disclosure. Referring to FIG. 4,the air purifier 300 can have substantially the same configuration asthe air purifier 100 in accordance with the first embodiment of thepresent disclosure, except that the air purifier 300 includes a firstair purification unit 40 and a second air purification unit 50, whichserve together as the air purification unit. The first air purificationunit 40 and the second air purification unit 50 are sequentiallyarranged along an air flow path to have the second air purification unit50 disposed over the first air purification unit 40. Thus, the followingdescriptions will be focused on components that are different from thoseof the first embodiment of the present disclosure, in order to excludeduplicate descriptions.

Referring to FIG. 4, the first air purification unit 40 can include afirst UV light source 410 including sterilization UV LEDs 412 and acollection filter 222. The first UV light source 410 can include a PCB411 with the sterilization UV LEDs 12 arranged on the PCB 411, and alight reflecting structure 414 disposed to surround the sterilization UVLEDs 412.

The second air purification unit 50 can include a second UV light source510 including photocatalyst UV LEDs 512 and a photocatalyst filter 224.The second UV light source 510 can include a PCB 511 with thephotocatalyst UV LEDs 512 arranged on the PCB 511, and a lightreflecting structure 514 disposed to surround the photocatalyst UV LEDs512.

The first air purification unit 40 can primarily sterilize air flowingthrough an air duct or a fluid control structure 140, and the second airpurification unit 50 can deodorize and sterilize the air having passedthrough the first air purification unit 40.

In other embodiments, the positions of the first air purification unit40 and the second air purification unit 50 can be switched to eachother. Thus, the second air purification unit 50 can primarily deodorizeand sterilize the air flowing through the air duct or fluid controlstructure 140, and the first air purification unit 40 can sterilize thedeodorized and sterilized air having passed through the first airpurification unit 40.

FIG. 5 is a schematic plan top-down view of an exemplary UV light sourcein accordance with an embodiment of the present disclosure. For example,the UV light source can include the first UV light source 410 describedwith reference to FIG. 4.

Referring to FIG. 5, the first UV light source 410 can include the PCB411 having through-holes 416 formed therein. The sterilization UV LEDs412 can be arranged on the PCB 411. The sterilization UV LEDs 412 can bearranged to form rows as illustrated in FIG. 5. However, the arrangementof the sterilization UV LEDs 412 is not limited to the one shown in FIG.5, and the sterilization UV LEDs 412 can be arranged in various manners.

The light reflecting structure 414 can be disposed to surround thesterilization UV LEDs 412. The inner wall of the light reflectingstructure 414 can include a coating layer formed of aluminum or silver,which has high light reflection efficiency. In another embodiment, thelight reflecting structure 414 can be formed of aluminum or silver. Thelight reflecting structure 414 can be connected to the PCB 411 through aconnection member 415, and structurally supported by the PCB 411 and theconnection member 415. The shape and structure of the connection member415 can be implemented in various suitable configurations, includingconfigurations based on or based at least in part on a variety ofpublicly-known support structures.

In other embodiments, the UV light source can include the second UVlight source 510 described with reference to FIG. 4. The second UV lightsource 510 can have substantially the same configuration as the firstlight source 410, except that the photocatalyst UV LEDs 512 are mountedon the PCB 511 rather than the sterilization UV LEDs 412.

FIG. 6 schematically illustrates an exemplary air purifier in accordancewith a third embodiment of the present disclosure. FIG. 7 is a schematiccross-sectional view of the air purifier of FIG. 6. Referring to FIGS. 6and 7, the air purifier 600 can include a case 610, a fan 620, a filterunit 630, and other components including a fluid control structure.

The case 610 can include an air inlet 612 and an air outlet 614, andhave an air flow path from the air inlet 612 to the air outlet 614. Thecase 610 can form a frame of the air purifier 600.

The fan 620 can be disposed in the case 610 adjacent to the air inlet612 to introduce air into an internal space of the case 610. The fan 620can include a blower fan, for example. The fan 620 can include an inlet622 adjacent to and substantially aligned with the air inlet 612 toexpedite flow of air into the internal space of the case 610. The fan620 can include an outlet 620 for discharging introduced air towards thefilter unit 630. As illustrated in FIGS. 6 and 7, the fan 620 can takeair through the air inlet 612 and allow air flow in the direction of arotation axis of the fan 620, that is, the Y-axis direction. The fan 620can discharge air flowing in a direction perpendicular to the rotationaxis of the fan 620, that is, the Z-axis direction.

When the fan 620 including a blower fan is applied to the case 610, theoutlet 624 of the fan 620 can have a smaller cross-sectional area thanthat of the air flow path formed at least partially by the fluid controlstructure 640 inside the case 610. Furthermore, a central axis of theoutlet 624 of the fan 620 can be positioned at one side from the centralaxis of the case 610. That is, as illustrated in FIG. 6, the centralaxis of the outlet 624 of the fan 620 can be separated at apredetermined distance from the central axis of the case 610 in the X-or Y-axis direction.

In the above-described structure, the air discharged from the outlet 624of the fan 620 can stay around or near the outlet 624 for the fan 620 orflow toward a bottom of the case 610. Furthermore, as the air dischargedfrom the outlet 624 of the fan 620 is focused in one direction, thedischarged air can be introduced into the filter unit 630 only through apart of the surface of the filter unit 630.

In order to solve the problem described in the previous paragraph, thefluid control structure or air duct 640 can be disposed between the fan620 and the filter unit 630. The fluid control structure 640 can controlan air flow between the outlet 624 of the fan 620 and the filter unit630. The fluid control structure 640 can be disposed to change thespeed, direction, and density of the air flow around the fluid controlstructure 640.

In the present embodiment, a fluid duct or air duct 640 serving as thefluid control structure 640 can be disposed to extend from the outlet624 of the fan 620 toward the inner wall of the case 610. The fluid ductor air duct 640 can control air flow between the outlet 624 of the fan620 and the filter unit 630.

As illustrated in the drawings, the fluid duct or air duct 640 caninclude a first duct part 641, a second duct part 643, and a third ductpart 642. The first duct part 641 can be extended from the outlet 624 ofthe fan 620 toward the inner wall of the case 610. The second duct part643 can be connected to the first duct part 641 through the third ductpart 642 and extend in the opposite direction as the first duct part 641and away from the inner wall of the case 610. The third duct part 642can be connected to the first and second duct parts 641 and 643respectively and extend in a direction parallel to the inner wall of thecase 610.

The first duct part 641 can serve to prevent or substantially preventthe air discharged from the outlet 624 of the fan 620 from stayingaround or near the outlet 624 or flowing toward the bottom of the case610, and spread the discharged air to the internal space of the case610. The second duct part 643 can be disposed to have a predeterminedangle with respect to the longitudinal direction of the case 610. Thatis, as the second duct part 643 is bent at a predetermined angle towardthe inside of the case 610 and away from the inner wall of the case 610,the second duct part 643 can control the air discharged from the outlet624 of the fan 620 to converge on a central region of the case 610. Thethird duct part 642 can control the air flow in a state where the airdischarged from the outlet 624 of the fan 620 is spread to the entireinner region of the case 610 based on the cross-sectional area of thecase 610. In other embodiments, without the third duct part 642, thefirst duct part 641 can be directly connected to the second duct part643.

The filter unit 630 can be disposed over the fluid control structure640. The filter unit 630 can include a first filter 632 and a secondfilter 634 disposed over the first filter 632. For example, the firstfilter 632 can be implemented with a deodorization filter, and thesecond filter 634 can be implemented with a sterilization filter. Foranother example, the first filter 632 can be implemented with afiltration filter, and the second filter 634 can be implemented with adeodorization filter. As such, the filter unit 630 can include variousfilters or combination of filters which are sequentially arranged withone above another. The first and second filters 632 and 634 can performa variety of functions including but not limited to deodorization,sterilization, and filtration. FIGS. 6 and 7 illustrate that the filterunit 630 includes two filters, that is, the first and second filters 632and 634. However, the number of filters forming the filter unit 630 isnot limited to two.

As the fluid duct is applied as the fluid control structure 640 asdescribed above, the air discharged from the outlet 624 of the fan 620can be more uniformly introduced into the filter 630. As the flowing airis uniformly spread on a surface area of the filter unit 630, the airpurification efficiency of the filter unit 630 can be improved.

In other embodiments, a UV LED unit can be arranged under the filterunit 630. The UV LED unit can have substantially the same configurationas the light source 210 described with reference to FIG. 1. That is, theUV LED unit can include the above-described photocatalyst UV LEDs or theabove-described sterilization UV LEDs or both types of UV LEDs.

When the UV LED unit includes the photocatalyst UV LEDs, the filter unit630 disposed adjacent to or above the UV LED unit can include aphotocatalyst filter. When the UV LED unit includes the sterilization UVLEDs, the filter unit 630 can include a collection filter to collectbacteria from the air discharged from the outlet 624 of the fan 620.

FIG. 8 is a schematic cross-sectional view of an exemplary air purifierin accordance with a fourth embodiment of the present disclosure.Referring to FIG. 8, an air purifier 700 can have substantially the sameconfiguration as the air purifier 600 described with reference to FIGS.6 and 7, except that the air purifier 700 additionally includes aplate-shaped structure 644 serving as a fluid control structure. Thus,the following descriptions will be focused on components that aredifferent from the air purifier 600, in order to exclude duplicatedescriptions.

The plate-shaped structure 644 can be disposed in the fluid duct 640 asshown in FIG. 8. The plate-shaped structure 644 can have one surfacedisposed to face the air flow path direction so as to interfere with airflow within the case 610. For example, the one surface of theplate-shaped structure 644 can be disposed in a direction which issubstantially perpendicular to the flow path direction of the airdischarged from the outlet 624 of the fan 620. For another example, theone surface of the plate-shaped structure 644 can be disposed to have aslope at a predetermined angle with respect to the flow path directionof the air discharged from the outlet 624 of the fan 620.

As illustrated in FIG. 8, the plate-shaped structure 644 can interferewith the air discharged from the outlet 624 of the fan 620, and an airflow can be formed to avoid the plate-shaped structure 644. Theplate-shaped structure 644 and the fluid duct 640 can be applied toproperly control the flow of air flowing toward the filter unit 630.That is, the plated-shaped structure 644 can prevent the concentrationof air flow on a specific region of the filter unit 630, caused by thestructure of the fan 620. Furthermore, while the air passes through theplate-shaped structure 644, the flow velocity of the air can be slowedto increase the time during which the air reacts with the filter unit630.

The configuration and arrangement of the plate-shaped structure 644 andthe fluid duct 640 can be determined through a structure of the outlet624 of the fan 620, a discharge performance of the fan 620 (that is, thedischarge flow rate and the discharge flow velocity), and an internalstructure of the case 610.

In other embodiments, a UV LED unit can be disposed under or below thefilter unit 630. The UV LED unit can have substantially the sameconfiguration as the UV light source 210 described with reference toFIG. 1. That is, the UV LED unit can include the above-describedphotocatalyst UV LEDs or the above-described sterilization UV LEDs orboth types of UV LEDs.

When the UV LED unit includes the photocatalyst UV LEDs, the filter unit630 disposed adjacent to or above the UV LED unit can include aphotocatalyst filter. When the UV LED unit includes the sterilizationLED units, the filter unit 630 can include a collection filter tocollect bacteria.

FIG. 9A is a schematic cross-sectional view of an exemplary air purifierin accordance with a fifth embodiment of the present disclosure. FIG. 9Bis a schematic plan view of an exemplary fluid control structure appliedto the air purifier of FIG. 9A. Referring to FIGS. 9A and 9B, the airpurifier 800 can have substantially the same configuration as the airpurifier 600 described with reference to FIGS. 6 and 7, except that theair purifier 800 additionally includes a plate-shaped structure 645having through-holes formed on the plate-shaped structure 645 andserving as a fluid control structure or a part of a fluid controlstructure. Furthermore, the plate-shaped structure 645 can havesubstantially the same configuration as the plate-shaped structure 644of the air purifier 700 described with reference to FIG. 8, except thatthe plate-shaped structure 645 has through-holes formed on theplate-shaped structure 645. Thus, the following descriptions will befocused on components that are different from the plate-shaped structure644, in order to exclude duplicate descriptions.

Referring to FIG. 9B, the plate-shaped structure 645 can include a framepart 645 a having through-holes 645 b formed on the frame part 645 a.The frame part 645 a can serve to interfere with air flows. The airflowing to the plate-shaped structure 645 can pass through thethrough-holes 645 b of the plate-shaped structure 645. The through-holes645 b of the plate-shaped structure 645 can be formed in a proper shapeto control the flow of air flowing toward the filter unit 630. That is,the plate-shaped structure 645 can prevent the concentration of the airflow on a specific region of the filter unit 630, caused by thestructure of the fan 620. Furthermore, while the air passes through theplate-shaped structure 645, the flow velocity of the air flowing throughthe plate-structure 645 can be slowed to increase the time during whichthe air reacts with the filter unit 630. The size and arrangement of thethrough-holes 645 b can be determined through the structure of theoutlet 624 of the fan 620, the discharge performance (that is, dischargeflow rate and discharge flow velocity) of the fan 620, and the internalstructure of the case 610.

In other embodiments, a UV LED unit can be disposed under the filterunit 630. The UV LED unit can have substantially the same configurationas the UV light source 210 described with reference to FIG. 1. That is,the UV LED unit can include the above-described photocatalyst UV LEDs orthe above-described sterilization UV LEDs or both types of UV LEDs.

When the UV LED unit includes the photocatalyst UV LEDs, the filter unit630 disposed adjacent to or above the UV LED unit can include aphotocatalyst filter. When the UV LED unit includes the sterilizationLED units, the filter unit 630 can include a collection filter tocollect bacteria.

FIG. 10A is a schematic cross-sectional view of an exemplary airpurifier in accordance with a sixth embodiment of the presentdisclosure. FIG. 10B is a schematic plan top-down view of an exemplaryfluid control structure applied to the air purifier of FIG. 10A.

Referring to FIGS. 10A and 10B, the air purifier 900 can havesubstantially the same configuration as the air purifier 600 describedwith reference to FIGS. 6 and 7, except that the air purifier 900additionally includes a spherical structure 647 serving as a fluidcontrol structure. Thus, the following descriptions will be focused oncomponents different from air purifier 600, in order to excludeduplicate descriptions.

The spherical structure 647 can generate a vortex through a pressuredifference when air flows on the outer circumferential surface of thespherical structure 647. Such a vortex can serve to mix the air flowingthrough the fluid control structure such that the air reaches the filterunit 630 in a more uniform state.

Referring to FIG. 10B, the spherical structure 647 can include sphericalstructure parts 647 a and a frame part 647 c for connecting thespherical structure parts 647 a, and the frame part 647 c can havethrough-holes 647 b formed on the frame part 647 c. The sphericalstructure parts 647 a can have such a size as to generate vortexesaround the structure parts 647 a. The size and arrangement of thespherical structure parts 647 a can be determined through a structure ofthe outlet 624 of the fan 620, a discharge performance (that is,discharge flow rate and discharge flow velocity) of the fan 620, and aninternal structure of the case 610.

In other embodiments, a UV LED unit can be disposed under the filterunit 630. The UV LED unit can have substantially the same configurationas the UV light source 210 described with reference to FIG. 1. That is,the UV LED unit can include the above-described photocatalyst UV LEDs orthe above-described sterilization UV LEDs or both types of UV LEDs.

When the UV LED unit includes the photocatalyst UV LEDs, the filter unit630 disposed adjacent to or above the UV LED unit can include aphotocatalyst filter. When the UV LED unit includes the sterilizationLEDs, the filter unit 630 can include a collection filter to collectbacteria from the air discharged from the outlet 624 of the fan 620 andflowing through the filter unit 630.

FIG. 11A is a schematic cross-sectional view of an exemplary airpurifier in accordance with a seventh embodiment of the presentdisclosure. FIG. 11B is a schematic plan top-down view of a UV LED unitapplied as a fluid control structure of the air purifier of FIG. 11A.

Referring to FIGS. 11A and 11B, the air purifier 1000 can havesubstantially the same configuration as the air purifier 600 describedwith reference to FIGS. 6 and 7, except that a UV LED unit 648 isapplied as a fluid control structure. Thus, the following descriptionswill be focused on components that are different from the air purifier600, in order to exclude duplicate descriptions.

The UV LED unit 648 can include a PCB 648 a having through-holes 648 bformed on the PCB 648 a and UV LEDs 648 c and 648 d arranged on the PCB648 a.

In accordance with the seventh embodiment, the UV LEDs 648 c and 648 dcan react with the filter unit 630 to perform a sterilization ordeodorization action. For example, when the UV LED 648 c is aphotocatalyst LED 648 c, the first or second filter of the filter unit630 can include a photocatalyst filter. The photocatalyst filter canemit UV rays with a wavelength of about 700 to 800 nm such that the UVrays react with the photocatalyst medium of the photocatalyst filter.Through the photocatalytic reaction, hydroxyl radicals having strongoxidizing power can be generated to perform a sterilization ordeodorization action. For another example, when the UV LED 648 c is asterilization LED, the first or second filter of the filter unit 630 caninclude a collection filter. The collection filter can collect bacteriain the flowing air discharged from the outlet 624, and the sterilizationLED can sterilize the collected bacteria by emitting UV rays with awavelength of about 200 to 700 nm onto the bacteria. In otherembodiments, the UV LEDs 648 c and 648 d can be implemented with onlyphotocatalyst LEDs or sterilization LEDs.

In the present embodiment, the PCB 648 a having the UV LEDs 648 c and648 d mounted on the PCB 648 a can be applied as the fluid controlstructure. The PCB 648 a can pass air flowing through the through-holes648 b, and the other parts of the PCB 648 a excluding the through-holes648 b can be used to interfere with the air flow. As such, the PCB 648 ahaving the through-holes 648 b formed on the PCB 648 a can be applied toprevent or substantially prevent the concentration of air flow on aspecific region of the filter unit 630, which is caused by the structureof the fan 630. While the air passes through the PCB 648 a, the flowvelocity of the air can be slowed to increase the time during which theair reacts with the filter unit 630. At this time, the size andarrangement of the through-holes 648 b can be determined through thestructure of the outlet 624 of the fan 620, the discharge performance(that is, discharge flow rate and discharge flow velocity) of the fan620, and the internal structure of the case 610.

In other embodiments, a structure capable of slowing the flow velocityof air can be additionally disposed under the filter unit 630. Such astructure can include a cabin filter having a large pressure differencebetween front and rear stages, for example. As the air flow is slowed bythe cabin filter, the time during which the air flow stays in the filterunit 630 can be sufficiently secured to increase the sterilization ordeodorization efficiency of the filter unit 630.

FIG. 12 is a schematic cross-sectional view of an exemplary air purifierin accordance with an eighth embodiment of the present disclosure. FIG.13A is a cross-sectional view of the air purifier of FIG. 12, seen froma direction A, an exemplary direction. FIG. 13B is a cross-sectionalview of the air purifier of FIG. 12, seen from a direction B, anotherexemplary direction different from direction A.

Referring to FIGS. 12, 13 a, and 13 b, the air purifier 1100 can includea case 710 having a first air inlet 712 and an air outlet 714. The case710 can include a frame forming an exterior structure of the airpurifier 1100. Referring to FIGS. 12 and 13A, the first air inlet 712can be formed at a side of the case 710, and the air introduced into thecase 710 through the first air inlet 712 can be introduced to a fan 720through a second air inlet 713. The fan 720 can include a blower fan,for example.

The air introduced through the second air inlet 713 can be introducedinto a fan inlet 722 through the first filter unit 730. The first filterunit 730 can include a variety of functional filtration filters such asa dust filter, a collection filter, and a carbon filter, for example.The air introduced into the fan inlet 722 can be discharged through anoutlet 724 according to the operation of the fan 720.

The central axis of the outlet 724 of the fan 720 can be positioned atone side from the central axis of the case 710. As illustrated in FIG.13A, the central axis of the outlet 724 of the fan 720 can be separatedat a predetermined distance from the central axis of the case 710 in theY-axis direction.

The first fluid control structure 740 can be disposed at the top of theoutlet 724. The first fluid control structure 740 can include a firstduct inner wall 741 and a second duct inner wall 742. The first ductinner wall 741 and the second duct inner wall 742 can have anasymmetrical shape with each other with respect to a central axis of theair duct along the height direction of the case 710. For example, thefirst duct inner wall part 741 and the second duct inner wall 742 canhave various shapes such as a curve and a straight line. Furthermore,the first and second inner walls 741 and 742 can have substantially thesame shape as the fluid control structure 640 described with referenceto FIGS. 6 and 7.

The first fluid control structure 740 can further include a controlstructure 743 within the duct. The control structure 743 can include theplate-shaped structure 644 described with reference to FIG. 8, theplate-shaped structure 645 having the through-holes and described withreference to FIGS. 9A and 9B, or the plate-shaped structure 647described with reference to FIGS. 10A and 10B. The control structure 743can have various shapes such as a straight line and a curve, forexample. As described above, the first fluid control structure 740 cancontrol the flow of air which is discharged from the outlet 724 andflows into the filter unit 760.

A UV LED unit 750 can be disposed adjacent to the first fluid controlstructure 740. When the first fluid control structure 740 has a ductshape, the UV LED unit 750 can be disposed in the first fluid controlstructure 740 serving as the duct or at least a part of the duct.

The UV LED unit 750 can include a PCB 752 and UV LEDs 754 mounted on thePCB 752. The UV LEDs 754 can include the above-described sterilizingLEDs or the above-described photocatalytic LEDs or both.

The filter unit 760 can be disposed over the UV LED unit 750. Asillustrated in the drawings, the filter unit 760 can include aphotocatalyst filter 762 and a collection filter 764. The photocatalystfilter 762 can function with the photocatalyst LEDs of the UV LED unit750. Furthermore, the collection filter 764 can function with thesterilizing LEDs.

As illustrated in FIG. 13A, the PCB 752 of the UV LED unit 750 can beinclined at a predetermined angle with respect to the filter unit 760.That is, the surface of the PCB 752 can be disposed so as not to beparallel to the surface of the filter unit 760. Thus, the frequency atwhich light emitted from the UV LEDs 754 collides with a mesh of thefilter unit 760 can be increased to improve the efficiency of thephotocatalytic reaction with a photocatalytic material applied on themesh or the sterilization action for bacteria collected in the mesh.

A second fluid control structure 770 can be disposed over the filterunit 760. The second fluid control structure 770 can be disposed toextend to the air outlet 714. The second fluid control structure 770 caninclude an air or fluid duct having a first duct inner wall 771 and asecond duct inner wall 772. The first duct inner wall 771 and the secondduct inner wall 772 can have an asymmetrical shape with each other withrespect to the central axis of the duct along the height direction ofthe case 710. For example, the first duct inner wall 771 and the secondduct inner wall 772 can have various shapes such as a straight line anda curve. Furthermore, the first duct inner wall 771 and the second ductinner wall 772 can have substantially the same shape as the fluidcontrol structure 640 described with reference to FIGS. 6 and 7.

The second fluid control structure 770 can further include a controlstructure 773 within the duct. The control structure 773 can include theplate-shaped structure 644 described with reference to FIG. 8, theplate-shaped structure 645 having the through-holes and described withreference to FIGS. 9A and 9B, or the spherical structure 647 describedwith reference to FIGS. 10A and 10B. The control structure part 772 canhave various three-dimensional shapes such as a straight line and acurve. The second fluid control structure 770 can control the flow ofair which is discharged through the filter unit 760 and flows into theair outlet 714.

Only a few embodiments, implementations and examples are described andother embodiments and implementations, and various enhancements andvariations can be made based on what is described and illustrated inthis document.

What is claimed is:
 1. An air purifier comprising: a case having a firstsurface, a second surface opposing the first surface, and a sidewallconnecting the first surface and the second surface, an air inlet and anair outlet; a fan disposed inside the case and adjacent to the airinlet; an ultraviolet (UV) light emitting diode (LED) unit and a filterunit arranged inside the case and over the fan along a flow path of air;and a fluid control structure disposed inside the case and positionedbetween the fan and the UV LED unit, the fluid control structureincluding a first duct part coupled to an outlet of the fan and havingan increasing width along the flow path of air and a third duct partextending from the first duct part in a direction parallel to thesidewall of the case, wherein the fluid control structure controls anair flow along the flow path of air between the outlet of the fan andthe filter unit.
 2. The air purifier of claim 1, wherein the outlet ofthe fan has a smaller cross-sectional area than that of the filter unitof the case.
 3. The air purifier of claim 1, wherein the fluid controlstructure further comprises: a second duct part disposed closer to thefilter unit than the fan and extended in a direction away from thesidewall of the case.
 4. The air purifier of claim 3, wherein the secondduct part has a predetermined angle with respect to a longitudinaldirection of the case.
 5. The air purifier of claim 1, wherein the fluidcontrol structure comprises a plate-shaped structure having a surfacedisposed to face the flow path of the air within the case.
 6. The airpurifier of claim 1, further comprising a light reflecting structuredisposed to surround the UV LED unit.
 7. The air purifier of claim 1,wherein the UV LED unit is structured to emit UV light within awavelength range that can directly sterilize air by illuminating theair.
 8. The air purifier of claim 1, wherein: the filter unit includes aphotocatalyst material that reacts to UV light to cause photocatalyticreactions that sterilize the air; and the UV LED unit emits UV lightwithin a wavelength range that can cause photocatalytic reactions in thephotocatalyst material, and is configured to direct the UV light ontothe photocatalyst material.
 9. The air purifier of claim 1, furthercomprising an air purification unit disposed over the fan to receive andpurify air discharged from the outlet of the fan.
 10. The air purifierof claim 1, wherein the UV LED unit includes UV LEDs that emit UV lightat different UV spectral ranges from each other.
 11. The air purifier ofclaim 1, wherein the UV LED unit includes an UV LED emitting UV lightwithin a wavelength range from 200 nm to 300 nm.
 12. The air purifier ofclaim 1, wherein the UV LED unit includes an UV LED emitting UV lightwithin a wavelength range from 300 nm to 400 nm.
 13. The air purifier ofclaim 1, wherein the filter unit includes titanium oxide (TiO₂), zincoxide (ZnO), tungsten oxide (WO₃), or zirconium oxide (ZrO₂).
 14. Theair purifier of claim 1, wherein the fluid control structure includes afirst duct inner wall and a second duct inner wall that are asymmetricalwith respect to a central axis of the fluid control structure.
 15. Theair purifier of claim 1, wherein the fluid control structure includes aportion that faces the filter unit, the portion has a width covering thefilter unit.
 16. The air purifier of claim 1, wherein the air inlet islocated in the sidewall and the air outlet is located in one of thefirst surface and the second surface.
 17. The air purifier of claim 1,further comprising: an additional fluid control structure disposed overthe filter unit and extended to the air outlet, the additional fluidcontrol structure having a decreasing width along the direction parallelto the sidewall of the case.
 18. The air purifier of claim 1, whereinthe outlet of the fan is positioned closer to the sidewall than acentral axis of the case.